Coating material recovery medium



March 6, 1945. I 5 SAUNDERS AL Re. 22,615

COATING MATERIAL RECOVERY MEDIUM AND PROCESS Original Filed Sept. 10, 1941 v INVENTORS, I I fe a/7x024) jaynJers,

M0/7Z J6/Z Reiaued Mar. 6, 1945 COATING MATERIAL RECOVERY MEDIUM AND PROCESS Seymour G. Saunders, Bloomfield Hills, and Harry Morrison, Detroit, Mich., assignors to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware Original No. 2,328,399, dated August 31, 1943,

Serial No. 410,268, September 10, 1941. Applicationfor reissue January 5, 1944, Serial No.

This invention relates to an improved apparatus and process for reconditioning recovered solids of excess sprayed coating materials which have been collected in a recovery medium mainly comprising water.

More particularly, the invention pertains to a process for the removal of water or other recovery medium from recovered excess sprayed coating material whereby the latter is conditioned for reuse.

' One of the main objects of the invention is to provide an efficient and economical process and apparatus for removing recovery medium from collected excess sprayed coating material which has been collected in accordance with the disclosures in Patents Nos. 2,086,514 and 2,208,646 issued July 6, 1937 and July 23, 1940, respectively for an improvement in coating material recovery process.

Another object of the invention is the provision of a process of this character which operates enlciently at maximum temperatures far below the boiling temperature of water. i

A further object of the invention is the provision of a process of this kind during which the solids are incorporated for reuse in the vehicle or solvent in which such coating material solids are conventionally used. 7

A still further object of the invention is the utilization in a process of this kind of the same solvent for the purpose of extracting occluded water from the solids as is conventionally used in reducing the latter to a sprayable consistency.

An additional object of the invention is the provision in a process of this character for the reuse, in a continuous repeating cycle, of the fraction of solvent utilized to extract the occluded water from the solvents.

An illustrative embodiment of the invention is shown in the accompanying drawing in which the figure is a diagrammatic side elevational view, partly in section, of apparatusfor separating recovery medium from recovered solids of excess sprayed coating material in accordancewith the 1 Claim. (oi.- 106-287) patents. When the particles of excess sprayed coating material are precipitated or otherwise deposited in such form that they collect as a sludge at the bottom of a settling tank or accumulate in scum-like formation on the surface of the liquid of the tank, depending upon the nature of sludge, the latter is removed from the settling tank and conveyed in a bucket ill by conveyor mechanism, generally designated by the numeral II, to a hopper [2 which discharges the sludge into the interior of a mixing tank generally designated by the numeral 13. The hopper I2 is provided with-a removable closure l2 which is adapted to seal the inlet end thereof when it is in closed position. The mixing tank I3 is provided with a steam jacket I4 or other suitable means by which it may be heated. Steam is admitted to the jacket through an inlet pipe l5, circulated therethrough and discharged from the jacket through an outlet pipe l6. Disposed in the inner chamber H of the mixing tank are suitable mixers I8 which are driven by a motor 19. An auxiliary solvent container 20 is connected by a pipe 2| with the inner chamber ll of the mixing tank for the purpose of supplying a suitable solvent thereto. The solvent employed in this process preferably comprises the same sol vent or vehicle which is conventionally used in the finished coating material of the type being operated upon. High solvent naphtha, toluol, mixtures of 'toluol and naphtha, xylol, and mixtures of naphtha of diflferent boiling points are examples of suitable solvents which may be used for this purpose. A small amount of butyl alcohol may be added to the solvent for the purpose of, protecting certain resins against detrimental effect by heat during the distillation step. The 

